Counterintuitive Alert: Straight Hair Gets More Tangled

Curly fibers pass like ships in the night.

While teaching physics at École Polytechnique in France, physicist Jean-Baptiste Masson used hair fibers as an example of a complex system that could be modeled simply. The example made him wonder: Does curly hair get more tangled than straight hair? He thought that a person sporting, say, Shakira’s mane of curls would have more kinks than someone with pin-straight hair, but he wasn’t sure.

So Masson enlisted hairdressers to count the tangles in 123 limp-locked people and 89 curly-haired people. Straight hair had an average of 5.3 tangles, nearly twice as many as curly hair. Masson then created a model to help him understand why straight hair is, oddly, more prone to knotting. His answer: The greater the angle of intersection, the more likely the hair will knot. Curly strands intersect more often, but strands of straight hair rubbing together at steeper angles than curly hair make for more knots.